Alkene halogenation
Abstract
Alkene halogenation is a reaction in which a dihalogen (typically Br2 or Cl2) adds across the double bond of an alkene, yielding a vicinal dihalide, where one halogen atom is added to each carbon of the former double bond.
Keywords
Alkene, Alkyl dihalide
Category
Alkene
Mechanism
First, 𝜋 electrons of the alkene act as nucleophile and attack one of the halogen atoms of the dihalogen, polarizing the X-X bond and resulting in the departure of a halide ion.The first halogen atom bridges the two carbons of the former double bond, forming a cyclic halonium ion. Subsequently, the halide ion attacks one of the two carbons of the halonium ion from the back side, generating the corresponding vicinal dihalide in an anti configuration.
